卫伟教授课题组利用8-OHdG诱导的金纳米颗粒的手性组装，建立了圆二色谱检测8-OHdG的新方法。主要研究了不同尺寸金胶的组装以及不同长度的连接DNA对所组装的金胶二聚体CD信号的影响，得知20nm和25nm的金纳米颗粒由35bp的DNA连接时，其CD信号最大。我们利用DNA组装的金纳米粒子手性二聚体作为信号分子。当8-OHdG存在时，其于aptamer的亲和力大于aptamer与其互补链的亲和力，金胶二聚体结构被破坏，CD信号减弱。通过条件优化，检测的线性范围是0.05 to 2 nM，检测限可达33 pM，低于大多数关于8-OHdG的检测限。可以定量检测血液中的8-OHdG，对空白血清中做加标回收实验，准确度在92%到115%。该研究成果发表在Anal. Chem.，10.1021/acs.analchem.6b01258.
原理图
金胶尺寸及其手性组装信号
8-OHdG的检测
金胶二聚体的组装效率及方法的选择性
Table 1 Comparison of analytical performance of various methods for determination of 8-OHdG. | ||||
method | system | detection range | detection limit | reference |
fluorescence | triplex aptamer sensor | 3 ~ 100 nM | – | 2 |
CV | DNA/grapheme/glassy carbon electrode | 5.6 ~ 1155 nM | 0.875 nM | 12 |
LSV | poly(3-acetylthiophene)/GCE | 0.7 ~ 70 μM | 100 nM | 13 |
RLS | conformational switching of aptamer | 0.09 ~ 14.1 nM | 27 pM | 16 |
amperometry | dendrimer modified electrodes | – | 1.2 nM | 41 |
ECL | CQDs coated Au/SiO2 core-shell NPs | 0.7 ~ 70 nM | 0.3 nM | 42 |
UV-vis | G-quadruplex/hemin DNAzyme | 0.466 ~ 247 nM | 141 pM | 43 |
UV-vis | label-free aptamer and unmodified AuNPs | 5.6 ~ 282 nM | 1.7 nM | 44 |
DPV | poly(3-acetylthiophene)/GCE | 0.5 ~ 35 μM | 31.3 nM | 45 |
ELISA | a monoclonal antibody | – | – | 46 |
DPV | SWCNTs-Nafion/GCE | 0.03 ~ 1.25 μM | 8.0 nM | 47 |
HPLC/MS | direct injection of urine | – | 0.5 nM | 48 |
CD | chiroplasmonic assemblies of AuNPs | 0.05 ~ 2 nM | 33 pM | this work |
与文献方法的比较
Table 2 Recovery results of 8-OHdG added in 10% human serum samplesa. | ||||
Sample number | Added (nM) | Found (nM) | Recovery (%) | RSD (%, n = 5) |
1 | 0 | - | - | - |
2 | 0.2 | 0.21 | 115 | 7.27 |
3 | 0.4 | 0.37 | 92.5 | 5.66 |
4 | 0.6 | 0.58 | 96.7 | 5.25 |
5 | 0.8 | 0.82 | 103 | 4.89 |
6 | 1.0 | 1.07 | 107 | 6.18 |
aHuman serum samples are sampling from healthy donors at the Second Affiliated Hospital of Southeast University, Nanjing, China. | ||||
空白血清中8-OHdG的检测准确度验证实验
代表论文
Yuanjian Liu, Min Wei, Linqun Zhang, Wei Wei*, Yuanjian Zhang, Songqin Liu. Evaluation of DNA Methyltransferase Activity and Inhibition via Chiroplasmonic Assemblies of Gold Nanoparticles. Chem. Commun. 2015, 51, 76, 14350-14353.
Jingjing Ji, Yuanjian Liu, Wei Wei, Yuanjian Zhang, Songqin Liu*. Quantitation of DNA methyltransferase activity via chronocoulometry in combination with rolling chain amplification. Biosens. Bioelectron. 2016，85，25-31.
Linqun Zhang, Yuanjian Liua, Ying Li, Yuewu Zhao, Wei Wei,* Songqin Liu,* Sensitive electrochemical assaying of DNA methyltransferase activity based on mimic-hybridization chain reaction amplified strategy. Anal. Chim. Acta 2016，DOI:10.1016/j.aca.2016.05.044
Bingjing Lv, Min Wei, Yuanjian Liu, Xu Liu, Wei Wei*, Songqin Liu. Ultrasensitive photometric and visual determination of organophosphorus pesticides based on the inhibition of enzyme-triggered formation of core-shell gold-silver nanoparticles. Microchimic Acta. 2016, DOI: 10.1007/s00604-016-1939-8